Overhead welding gantry



Nov. 5, 1 940.

H. s. BOLES EI'AL OVERHEAD WELDING G-ANTRY NOV. 5, 1940. a BOLES ET AL 2,220,704

OVERHEAD WELDING GANTRY Filed May 21, 1957 6 Sheets-Sheet 2 NOV. 5, 940. H s BQLES ET AL OVERHEAD WELDING GANTRY Filed May 21. 1937 6 Sheets-Sheet 3 w r l 9 Jam 1/ 1321.

7 77 wal 'dfiiqggfz ATTORNEY.

NOV. 5, 1940. BQLES ETAL 2,220,704

- OVERHEAD WELDING GANTRY Filed May 21, 1937 e Sheets-Sheet 4 4/42 Qo/ehs BY 0wa7 6'0 017.

- TTORNEY.

Nov. 5, 1940. s BQLES ET AL 2,220,704

OVERHEAD WELDING GANTRY Filed May 21, 1937 6 Sheets-Sheet 5 M l I l I a A fl 1 Hi as N Nov. 5. 1940. H. s. BOLES ETAL OVERHEAD WELDING GANTRY Filed May 21, 1937 6 Sheets-,Sheet 6 QQ/WJ ATTORNEY.

Patented Nov. 5, 1940 UNITED STATES PATENT OFFICE 2,220,104 ovaarman WELDING GAN'IRY Harry S. Boles, Chicago, 111., and Howard 0.

Conn, Bay City, Mich.

Application Ma; 21, 1937, Serial No. 143,986

8 Claims.

Another object Of' the invention is to provide means for guiding the welding unit in a definite orbit of travel to conform to the general contour of the sheets or members being welded.

A further object is to provide a self-propelled antry having a revolvably mounted welding head or unit mounted and arranged whereby it can be easily and quickly adjusted for welding either longitudinal seams or cross seams, thereby providing flexibility of operation and reducing the labor incident to carrying on the work.

A still further object is to provide a portable overhead welding gantry including a welding head or .unit movable in a direction transverse to the direction or travel of the gantry for welding curved or'straight cross seams, said unit being adjustable and held stationary on the gantry for welding longitudinal seams as the gantry travels.

Wi h the above and other objects in view, the present invention consists in the combination and arrangement of parts, hereinafter more fully described, illustrated in the accompanying drawings. and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportion, and minor details of construction, without departing from the spirit, or sacrificing tages of the invention.

In the drawings:

Fig. 1 is a front elevational view of the portable welding device together with the welding fixture, showing the device set for welding cross seams.

Fig. 2 is an enlarged fragmentary sectional detail of the gantry drive sprocket and chain,

Fig. 3 is an enlarged fragmentary sectional detail showing one leg of the welding fixture asso ciated with the track.

Fig. 4 is a side elevational view of the apparatus.

Fig. 5 is a fragmentary top plan view of one side of the gantry.

Fig. 6 is an enlarged front view of the welding unit.

Fig. 7 is a topplan view of the welding unit,

- drive mechanism.

I fixture, welding any of the advan- Fig. 8 is an enlarged fragmentary sectional detail showing one of the flanged rollers of the welding unit.

Fig. 9 is an enlarged sectional detail showing the locking means for locking the welding unit in 5 position on the carriage.

Fig. 10 is a top view of a portion of the gantry drive mechanism.

Fig. 11 is an enlarged fragmentary, par-t sectional detail view of the welding unit carriage Fig. 12 is an end view of the welding unit carriage showing the same mounted on the gantry bridge.

Fig. 13 is a schematic wiring diagram of the motor control.

Fig. 14 is a schematic wiring diagram of the auxiliary control;

Fig. 15 is a schematic wiring diagram, showing the automatic pressure switch connection to the welding control panel.

Fig. 16 is a fragmentary sectional detail of the rolls, and work.

In order to weld large structures such as railroad cars, ships, houses, etc., during construction, it becomes necessary to bring the welding machine to the work, or the work to the welding machine. The curvature of the seams or joints also presents difilculties, and these difficulties we have overcome by providing a portable gantry inso eluding an adjustable, revolvably mounted weldmounted for travel on the gantry, so

welding head can be automatically moved along the work to weld cross seams, or

be set in proper position on the gantry to weld longitudinal seams as the gantry travels.

In accordance with the present invention a gantry structure is provided having power actuated means for moving the gantry along a system of parallel tracks, which tracks are provided with limit switches for limiting the travel of the gantry in either direction.

Overhead beams form a bridge which spans the gantry structure, and the welding unit carriage is mounted to travel on this bridge to progressively weld the cross seams, limit switches being also provided for limiting the travel of the carriage on the bridge.

In the present instance an apparatus is shown designed for use in the fabrication of railroad cars, and more particularly the top sheets thereof, the numeral l5 indicating the self-propelled gantry structure, which includes spaced apart trucks l8 and H respectively each truck comprising longitudinally spaced axle members i8 2 having track engaging wheels l9 mounted there on, said wheels travelling on a system of parallel tracks and 2! in theusual manner.

Fabricated superstructures or housings 22 and 23 respectively are mounted on the trucks l6. and I1. and suitably braced beams 2 and 25 trol panel 28 is mounted on the housing 22 withverse to the direction in easy reach of the operator and by means of which he can control the automatic movement of the gantry on the tracks, and also control the transverse or cross travel of the welding unit on the bridge, and in a manner to be presently described.

A suitable motor 29 is mounted on the housing 22, and a gear reduction unit 30 is located directly adjacent said motor. A transversely disposed shaft 3! projects from said unit 33, and a pulley 32 is mounted thereon. A similar pulley 33 is mounted on the motor, and a drive belt 34 is trained over these pulleys and serves to transmit motion to the shaft 3!.

A worm wheel 35 is mounted on said worm wheel meshing with and driving a worm 36 on a vertically disposed shaft 31 which shaft depends from the housing., The lower. end of shaft 3! is journaled in an ,axle, housing 38 provided on the axle i3. A worm 33 is mounted on the lower end of the shaft a worm wheel All mounted on the axle IS. A sprocket M is also mounted on said axle and engages a stationary chain G2 which is mounted on the chain support 53.

The opposite truck ll is driven in exactly the same manner, and from the same source of power as the truck la, through shaft 3!! journaled in bearings M depending from the bridge beam 25 and extending into a mounted on truck ll. It will'be obvious that the gantry will be moved and will travel on tracks 28 and 2! when the sprockets 49 are driven.

The ends of the beams 24 and 25 are secured in the housings 22 and 23 in any approved manner, said beams being shaped to follow the general curvature of the "wor as clearly shown in Fig. 1 of the drawings. The flanges of said beams form a track on which the welding unit B is adapted to travel.

The welding unit travels in a direction trans of travel of the gantry and includes a platform formedwith a centrally disposed opening 41, and a welding transformer B is suspended in said opening and is provided with flanged rollers 48 which engage and ride on the rim of the opening to revolvably support the transformer. Wheels 49 are journaled. on the corners of the platform 46 in the usual manner and engage and ride on the flanges of the bridge beams. Bearings 50 are cast integral with, and depend from said platform 46, and a shaft 5| is journaled in said bearings. Sprockets 52 are provided on the ends of the shaft and engage stationary chains 53, which are in turn secured to the lower flange of the bridge beams in any approved manner.

The welding unit is driven by means of -a reversible motor 54 which is mounted on the platform 46, and a gear housing 55 is mounted adjacent thereto, a worm shaft. 56 projecting from said housing, and a pulley 51 is mounted there- I 58 being provided on said motor, and a belt 59 is trained over these pulleys on, a similar pulley the shaft as,

31, meshing with of the work,

gear housing 55 netic forward starter for driving said worm shaft. A worm Si! is mounted on shaft 56, and meshes with and drives worm wheel 3! which is mounted on the shaft 62. Shaft 62 is journaled in the housing, a spur gear 83 being mounted on one end of said shaft and meshing with and driving a gear 64 mounted on the shaft 5!, and which also carries the sprockets which engage the chains 53, it, tho-refore, following that as the shaft 5| is driven, the welding unit carriage will move on the bridge of the gantry in the direction desired by the operator. H

Suitable locking mechanism (see Fig. 9) serves to secure the transformer and comprises welding head assembly in set position, and a pin 63 slidably mounted on the transformer shell, a lever t3 being pivotally mounted at 61 with its lower end engaging said pin, and suitable openings 68 are provided in the platform, the lever being adjustable to move the pin into or out of engagement with the'opening as desired. The transformer and welding head assembly is revolvable on the rolls 39 and 10 to proper predetermined position for welding either a cross or longitudinal-seam, and when the pin 65 is retracted the entire unit can be set as desired, and then looked in its set position.

Thewelding rolls 69 and 10 are each adjustably mounted in a holder H and are connected to one side of the secondary circuits of the transformer, thereby permitting the use of a relatively short strip of copper bar 12 on the opposite side which may be integral with the work holding fixture or jig C for making two seams simultaneously without any conventional, long secondary connection hooked on the opposite side of the work, and it is not deemed necessary to describe this welding unit in detail, as it is of standard design. It will be seen that Figure 16 discloses a series welding method for welding, roof sheets continuously. Applicants device may be used in connection with any kind of a welding system, for instance as spot welding.

The welding rolls are moved vertically by means of air cylinders 13, which are adjustable for spacing in conventional 'manner, and the welding heat is adjustable through control of the usual heat regulator 24.

The fwork fixture or jig "(3 is clearly shown in Fig. 1 of the drawings and comprises a plurality of spaced apart bents 15. The upper'edge of each bent is of the exact curvature of the top of the car, each bent being provided with legs 16, and each leg terminates in a channel shaped shoe 11 which is adapted to be secured to a track 18, said track being formed with spaced apart, inverted T shaped grooves 19, which accommodate bolts 80 for securely anchoring the fixture to the track.

In practise the sheets 8| are placed onthe fixture C and are clamped in position with their edges in abutting relation, and the welding unit is then-"set for welding the cross or longitudinal seams as above explained.

It will be noted that both motors have similar control circuits, (see Fig. 13) and include motors 29 and 82 respectively. Each circuit is of conventional forward and reversing magnetic starter type, the numerals 83 and 34 indicating the magand the magnetic reversing starter respectively, and are operated through pushbutton station 85. An automatic. braking condition is obtained through relay 88 which is mounted on and driven from the motor 82.

Limit switches 81 and II are provided for arresting the travel of the carriage, and when these switches are actuated the direction of-rotation of the motor 82 is reversed, the relay ll opens the circuit,

seams, and assuming the machine to be ready for unit carriage travel by meansof the limit switches 81 and I8, and limit switches 82 and 93 are also actuated for automatically raising the welding rolls from the move the gantry weld, and the operation is repeated.

For welding longitudinal seams, the welding unit must be rotated to bring the welding rolls to required position, the operator first swings the rotated ninety degrees and locked in set position by swinging locked position. The machine is now ready for welding longitudinal seams. The sequence of operation is exactly the same as above described for that the motor 29, which propels the gantry, is the carriage motor 54. An auxiliary switch 94 is provided for disconnecting the welding current for work" set-up and trial.

To prevent the welding rolls traveling crosswise of the work" when in down circuit is provided (see Fig. 14) including the relay 95 and limit switches 95 and 91 respectively, these are connected to both motor control circuits,'so that cross scams or longitudinal seams cannot be started unless welding rolls are set in their respective correct welding position.

The piping for the water cooling system is not shown or described, nor are the air lines for supplying air to the air cylinders etc. as they form no part of the present invention.

While in the present instance we have shown the apparatus equipped with welding rolls for seam welding, it will be understood that electrodes may be substituted for the rolls and that ly overlapping the spot welds, or intermittent spot welds of any desired spacing.

From the foregoing, it will be apparent that we have devised an improved welding apparatus of great flexibility, and by means of which large articles may be economically welded.

What we claim is:

1. A welding machine comprising wheel supported trucks, spaced arching beams connecting said trucks and adapted to be moved over stationary arched work during a welding operation, means for simultaneously traversing trucks through the rotation of their wheels, said means elding, the sequence the locking lever 56 to original energized instead of 1 the length of the beams, of means comprising a gantry adapted to be being controllable from one of said trucks and a welding carriage mounted on the beams and adapted to move longitudinally thereon to welding positions, means mounted on the welding carriage and cooperating with the beams for moving the carriage, said last named means comprising a driven gear carried by the carriage and a rack carried by one of the beams and with which the gear meshes.-

2. A device as set forth in claim 1 including supporting wheels for the carriage, trackways in the adjacent sides of the beams and in which the supporting wheels are mounted, a rack carried by the under side oi. each of the beams, a motor mounted on the carriage, a reduction gear train connection between the carriage and the rack bars and a driving connection between the 4. A device carriage and holding said carriage in various rotative adjusted positions and a combined seam and spot welding elementcarried by said head.

5. The combination with a traversing wheel supported welding gantry adapted to move over the curvature of the surface to be welded and a welding carriage between the beams and movably' guided therein, a controllable gear drive form distance from the work.

6. The combination with a welding machine comprising a travelling gantry having spaced beams upwardly arched with their ends curving downwardly and outwardly to opposite sides of work, a wheel supported welding carriage mounted on said beams and guided in the beams for following the contour 01' the work throughout for positively moving and guiding said carriage in its movement over the beams, said means comprising rack bars carried by the beams and following the contour thereof, a driven gear carried by the carriage and meshing with one of the rack bars and means carried by the carriage and having driving connection with the driven gear.

7. The combination with a welding machine disposed adjacent work, a travelling welding carriage mounted on said gantry, work engaging Welding elements carried by said carriage and means cooperating =.vith said Welding elements whereby said welding elements may be held in continuous engagement with the work at a uniform predeter= mined pressure for seam welding or for intermittent engagement with the work for spot welding.

8. The combination with a welding machine comprising a travelling gantry arching work, a welding marriage mounted on said gantry, means for moving said carriage transversely of the work,

said carriage being movable longitudinal of the work by the movement of the gentry. of a pivoted welding head mounted in said welding carriage,

aaaogoa v welding electrodes carried by said pivoted weld- HARRY S. HOLES. "HOWARD C. COGAN. 

